When to Plant Beets in Thunder Bay, ON
Beets are a dual-purpose root vegetable with edible roots and nutritious greens. They come in red, golden, and striped varieties and are rich in vitamins and minerals.
Thunder Bay, Ontario is in USDA Zone 4b. The average last spring frost is May 7 and the first fall frost is October 1, giving you a growing season of approximately 147 days.
At an elevation of 652 feet, Thunder Bay receives approximately 20.5 inches of rainfall annually with predominantly clay loam soil. Summer highs average 72°F, so choose short-season varieties of Beets to ensure they mature before fall. Clay soil retains moisture well for Beets, but amend with compost to improve drainage and prevent root rot.
Thunder Bay Soil Profile
Soil Type
Clay Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Beets Planting Risk Windows
Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.
How to Plant Beets
Fall planting: Sow 12 weeks before your first frost date for a fall harvest.
Beets Water Budget
Monthly Watering Guide for Beets
Beets needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.
| Month | Beets Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 0.9" | 0" | ❄️ Dormant |
| Feb | — | 1" | 0" | ❄️ Dormant |
| Mar | — | 1.2" | 0" | ❄️ Dormant |
| Apr | — | 1.8" | 0" | ❄️ Dormant |
| May | 3.5" | 2.6" | 0.9" | 💧 Light watering |
| Jun | 3.5" | 2.9" | 0.6" | 💧 Light watering |
| Jul | 3.5" | 2.5" | 1" | 💧 Light watering |
| Aug | 3.5" | 2" | 1.5" | 💧 Light watering |
| Sep | 3.5" | 1.6" | 1.9" | 🚿 Regular watering |
| Oct | 3.5" | 1.5" | 2" | 🚿 Regular watering |
| Nov | — | 1.3" | 0" | ❄️ Dormant |
| Dec | — | 1.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Thunder Bay). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Beets Heat Requirements (GDD)
What are Growing Degree Days (GDD)?
Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.
Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.
Beets Planting Timeline — Thunder Bay, ON
Beets Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | April 30 | Apr 30 – May 21 |
| Harvest | June 25 | Jun 25 – Jul 23 |
| Fall Sowing | July 9 | Jul 9 – Jul 23 |
Plant 0.5" deep · 4" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Direct Sow |
| May | Direct Sow |
| June | Harvest |
| July | Fall Sowing Harvest |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.8"/week · Only during dry spells
📅 Days to Maturity
50–70 days
🧪 Soil pH
Needs 6–7.5 · Your soil: N/A
🗺️ USDA Zone
Zone 4b
📆 Growing Season
147 days in Thunder Bay
Growing Tips for Thunder Bay
Soak seeds overnight before planting to improve germination. Thin seedlings to 3-4 inches apart. Harvest roots when 1.5-3 inches in diameter for best texture.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Isolate 1/2 mile from Swiss chard — same species, they will cross.
Beets in Other Locations
Frequently Asked Questions
When should I plant Beets in Thunder Bay, ON?
Thunder Bay is in Zone 4b with an average last frost of May 7. Plan your Beets planting based on this frost date — see the calendar above for exact timing.
What planting zone is Thunder Bay, ON?
Thunder Bay, Ontario is in USDA Hardiness Zone 4b. The average last spring frost is May 7 and first fall frost is October 1.
Your Thunder Bay Garden Planner — Free
A 22-page printable planner built for Thunder Bay (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.